Machine for bonding kraft paper to veneer sheet



Feb. 11, 1958 G. l. REYNOLDS ETAL 2 2,822,840

MACHINE FOR BONDING KRAFT 'PAPER To VENEER SHEET Filed Deo. 2'?, 1F54 2 sne'ts-shee: 1

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MACHINE FOR BONDING KRAFT PAPER TO VENER SHEET 2 Sheets-Sheet 2 Filed Dec. 27, 1954 United States Patent MACHINE FOR BONDING KRAFT PAPER TO VENEER SHEET Gilbert I. Reynolds, Port Blakely, and Axel A. Tallquist,

Seattle, Wash., assignors to Ederer Engineering Company, Seattle, Wash., a corporation of Washington Application December 27, 1954, Serial No. 477,816

4 Claims. (Cl. 144-279) This invention relates to a machine and method of producing, from veneer wood and kraft paper, a product hereinafter termed kraft veneer laminate, the said product being one in which the veneer sheet is sandwiched between sheets of the kraft paper so as to combine the stitfening quality of the veneer with the toughness of the paper. v

The general object of the invention is to provide a machine and method by which said operation of bonding paper to veneer may be performed expeditiously and at nominal expense.

This and other more particular objects and advantages will appear and be understood in the coursev of the following description and claims, the invention consisting in the new method and in the novel construction, adaptation and combination of parts hereinafter described and claimed.'

In the accompanying drawings:

VFigure l is a fragmentary side elevational view illustrating a machine constructed toembody the preferred teachings of the present invention, and incorporatinga showing of kraft paper and wood veneer as these com` ponents pass through the machine.

` Fig. V2 is a` fragmentary enlarged-scale longitudinal' vertical sectional view thereof; and

Fig; 3 is a fragmentary transverse vertical sectional view on line 3 3 of Fig. 2.

The steps practiced in producing the kraft veneer laminate will be here cursorily traced in thebelief that such will add to clarity in an understanding of the later detailed description of the machine and method. `Drawn from a respective supply reel an upper and a lower sheet Vof kraft paper are each given continuous travel along vguided travel paths andl in the course of such travel the said upper and lower paper, designated by P-1 and P-2,respectively, are each coated on one facing surface witha suitable cement or glue. For our glue we prefer to utilize a thermosetting adhesive such, for example,-as urea formaldehyde, resorcin formaldehyde, phenolformaldehyd'e, a plasticol, starch or silicate.

Following the application of such glue the said upper and; lower sheets of kraft paper are brought against the top Yand bottom face, respectively, of the veneer. Having moved along a separate path which merges with the paths travelled by the two sheetsV of kraft paper, the veneer-'- which isor may be,` composedof. transversely extending strips of scrap stock-in the meantime traverses a crowder table whereateach successive stripis overtaken by the next following strip so that the leading edge of such following stripsare brought against the .trailing edge of the preceding strip. `After"su`ch multi-strip sheet of veneer andthe twosheets of paper vare-brought together, pressure and'heatis'applied to effectuate'a bonding. I,

.Referring fto the drawings it will be seen that there are providedtwo successive horizontal conveyors of which the yfirst-acting cnveyorY performs n'the crowding function and-of which the other4 conveyor performs the bonding function. `lt is by these terms fcrowding and ,bonding that the4 two conveyo'r's'will be hereinafter referred to. The crowding conveyor'is composed of complementing u'pp'er ndlower members .whichfeach comprise a plurality of laterally spaced endless belts. The upper said ice belts, designated by 10, pass about lve and idler rollers 11 and 12, respectively, while the lower belts 13 pass about live and idler rollers 14 and 15, respectively. Beyond the tail end of such lower belts 13 and horizontally aligned with the upper run thereof is a rigid platformV 16, and as a lapping complement of this platform there are provided a plurality of bars 17. These bars are disposed longitudinally of the crowder conveyor in the interstice between the upper belts 10 and have their tail ends overlapping the platform 16. Upstanding rods 18 rigid with the bars are journaled for vertical slide movement in brackets 20 carried by a frame-work 21, and upon the upper ends of the rods there are provided weights 22. Said idler rollers 12 lie at the tail end of the concerned belt and are mounted upon a common spindle 23 journaled at each end in a respective block 24 vertically adjustable in a cage 25. The arrangement for driving these belts 10 and 13 is such that the upper belts have a speed accelerated by comparison with the speed of the lower belts. The upperbelts 10 terminate short of the lower belts, thus operating to close gaps from between successive strips of veneer as the vslower speed of strips propelled only by the lower belt 13 causes them to be overtaken by strips moving under the inuence of the faster upper belt 10.

.Like the crowder conveyor, the bonding conveyor is here shown as being also comprised of complementary upper and lower endless belts 26 and 27, respectively. These latter belts are, however, wide belts extending substantially the full width of the machine. In its endless travel the upper belt 26 is trained about a live drum 30 and idler rollers 3l, 32, 33 and 34. The lower belt 27 is trained about a live drum 35 and idler rollers 36, 37, 38 and 39. The upper run of the lower belt, passing from roller 39 to drum 35, is sustained upon a at table 40, and it is between this section of the lower belt and a paralleling lower run of the upper belt that the step of bonding kraft paper to veneer is performed, the merging of the three said separate preliminary paths travelled by the veneer sheet V and by the tWo paper sheets P-1 and P-2 occurring at the head end of these complementing-runs.

As to the kraft 'sheet P1, this being the lower sheet, the same is drawn from a reel. 29 journaled for free-turning movement in amounting box 41 and passes first around-an idler roll 42 and thence is fed into touching 1 the bonding conveyor.

contact with a'glue-spreading roll 43 which bears in turn against a dip roller 44 having its lower portion turning in a pot 45 containing glue. For the upper sheet of kraft paper, which is drawn from a reel 46, there is provided thev counterpart of the described gluing system, the pot, dip roller, and spreading roll being in this instance denoted by 47, 48 and 49, respectively.

ln the lower-run travel of the upper belt 26, and namely between the idler head roll 34 and the live drum 30, the

belt passes below a succession of longitudinally spaced apart transversely extending pressure rolls 50. `Trunnion shafts 51 at each end of these rolls are journaled in boxes 52 guided for vertical slide movement by rods 53, and pressing from above upon these boxes toV exert a yielding downward thrust thereon are respective compression springs 54.

In order to cure the thermo-setting glue applied by the spreading rolls 43 and 49 the laminated paper-veneerpaper product is caused to be heated as it movesv with We show, as the source of this heat, a plurality of infra-red tubes 56 such, for example, as the tubes illustrated and described in U. S. Patent #2,535,268. Associated with each of theseV tubes is a reflector, as 57, and the tubes are arranged in two top surface of the upper run of the upper belt 26, and

Patented Peb. 11, s

with the lower bank focusingits heat upon the top surface of the lower run of the lower belt 27. ln view of the heat-storage ability of the two cord-reinforced belts 26 and 27 and the inherent ability of infra-red heat to penetrate an object on which the heat is focused the particular surface of the belts onto which the infra-red heat is directed is immaterial. It should, however', be pointed out that the upper belt 26 can be deleted, retaining only the lower belt 27 as a conveyorin which case the heat from the upper bank of tubes must perforce be played directly on the conveyed product. It is for this reason that the upper bank of tubes are illustrated as having their heat rays directed downwardly.

It is believed that the invention will have been clearly understood from the foregoing-detailed description of our now preferred illustrated embodiment. Weiind; thaty a bonding zone 25 ft. in length used in conjunction with a belt speed approximating 50 ft. per minute, and with the temperature of the belts at the ingress end of the bonding zone in the neighborhood ofV 300 F., provides an ideal condition. The veneer used should be fairly dry, say with a moisture content, byrpreference, not in excess of One use for which the kraft veneer laminate produced by the present machine-is especially suited is thebottom, sides and top of a crate such, for example, asA the crates used in boxing fruit. Strips of the finished laminate are clipped to width so that the bottom, sides and top may be separate or, if desired, the veneer strips are or may be.

clipped to a predetermined necessary width before their lamination with the facing sheets, leaving the latter con-v tinuous through` the full combined width'of sides, bottom and top. It may occur, moreover, that spaces of moderate width are desired between these pre-clipped veneer strips in order to give the strips a freer hinge action after they have been joined bythe facing sheets of paper. In such case the crowding action is deleted and a spacing means substituted therefor.

Minor changes in the invention will suggest themselves and may be resorted to without departing from the spirit of therinvention, wherefore it is our intention that no limitations be implied and that the hereto annexed claims be given a scope fullyV commensurate with the broadest interpretation to which, the employed language admits.

We claim:

l. A machine for producing the described kraft veneer laminate and namely a laminate composed of wood veneer sandwiched between facing, sheets of` kraft paper, said machine comprising a generally horizontal bonding throat defined at the bottom by the upper run of a lower endless conveyor belt and at the top bythe lower run of an upper endless conveyor belt, both of said belts having high thermal capacity, a flat tableunderlying and giving support to said upper run of the lower conveyor belt, a series of transversely extending longitudinally spaced apart pressure rolls bearing from'above upon the lower run of said upper conveyor belt, a respective means for concentrating heat upon each of said conveyor belts so located as to apply its heat to the related belt along a section of the belts travel which is outside the bonding throat and thereby storing heat within said belt in advance of the traversal by said belt of the bonding throat, means for applyinga thermo-setting glue to one surface of each of the facing sheets, and means for bringing said glued surfaces against the opposite faces of the veneer and feeding the laminateV into the admission end of the bonding throat..

2. A machine for producing the described kraft veneer laminate, and namely a laminate composed of'a core of veneerisandwiched between facing sheets' of kraft paper, said machine comprising a generally horizontal bonding throat defined at the bottom bythe upper run of an endless conveyor belt and at the top by a series of transversely extending pressure rolls bearingupon said 'upper run of -meansy for applying a thermo-setting glue to one surface of each of the facing sheets, means for bringing said glued surfaces against opposite faces of the veneer and feeding the laminate into the admission end of the bonding throat, and means for heating the laminate as it moves through the throat so as to set said glue, the belt being a cord-reinforced strucmreofhigh' heat-storing capacity, said heating means performing its'heating function by concentrating heat rays upon the lower runof the conveyor belt, thus storing heatl tol bre-later transferred by conduction to the laminate in the upper-run travel of the belt.

3. A machine for producing the described kraft veneer laminate andnamely alaminatecomposed of wood veneer sandwiched between facing sheets of kraft paper, said machine comprising a generally horizontal bonding throat defined at the bottomby the upper runof a lower endless conveyor belt and at the top bythe lower run of anY upper endless conveyor belt,: both of said belts having. a high thermal capacity, a at table underlying and giving sup.- port to said upper run ofthe lower conveyor belt, a series of transversely extending longitudinally spaced apart pressure rolls bearing from above upon the lower run of said upper conveyor belt, a bank of infra-red heaters positioned so as to project their heat rays upon the upper run ofthe upper conveyor belt. so. as to. store heat within said belt before the belt reaches the bonding throat, a bank of infra-red heaters positioned so as to project their heat rays upon the lower run of the; lower conveyor belt to store heat in the lower belt likewise before the same reaches the bondingthroat, means for applying a thermo-setting glue to one surface of each of the facing sheets, and means for bringing said glued surfaces` against the opposite faces of the veneer Vand feeding the laminate into the admission (i endv of the bonding throat, the advance heating of the belts, insuring'a. curing temperature of highest intensity at the very advent of the laminates admission to the bonding throat and a progressively lowering temperature as the curing laminate, proceeding withV the belts through said bonding throat, draws the stored heat from the belts.

' 4. A machine for producing the described kraft veneer laminate and namely a laminate composed of wood veneer sandwiched between facing sheets of kraft paper, said machine comprising an endless conveyor belt having high thermal capacity, backing means giving support to the belt along one run thereof, means complementing said backed run of the belt to define a bonding throat between said complementingmeans'and the backed run of the belt, pressure means operativelyassociated with said belt, the backing means, and said complementing means so as to yieldingly press the complementing means towards the belt, a. means for concentratingheat upon the belt so located as to apply its heat along a section of the belts travel which is outsidethe bonding throat and thereby storing heat within said belt in advance of the traversal by said belt of the' bonding throatjmeans for applying a thermosettingglue to one surface 'of each of the facing sheets, and means for bringing said glued surfaces against the opposite faces of the veneer and feeding the laminate into the adthe belt at longitudinally spaced intervals thereof, meansV i Y underlying and giving support tosaid upper run of the belt,

mission end of the bonding throat.

References Cited in the le of this patent UNITED STATES PATENTS 709,864 Boenning Sept. 30, 1902 1,361,970 Dickey Dec. 14, 1920 1,427,971 Porter Sept. 5, 1922 1,450,060 Blossfeldr Mar. 27, 1923 1,999,253 l 'Norris. Apr. 30, 1935 2,459,279Y VHolden Jan. 18,1949 2,459,295 `Skoog Jan. 18, 1949 2,479,290' AuxierV et al. Aug. 16, 1949 2,488,759 yBolling i Nov. 22, 1949 2,490,819 Y jLambertlet al. Dec. 13, 1949 FOREIGN PATENTS 586,638 Great Britain Mar. 26, 1947 

